6v6 is a competitive format played in Team Fortress 2. It is played with a teamlimit of 6 players per team. Since the beginning of the competitive scene, many experiments with different formats were made, 6v6 was one of those, and it eventually stuck and today is widely accepted as the staple competitive format. It was the result of a lot of experimentation with class limits, unlocks and maps. It started out without enforced class limits, eventually the class limits got stricter (ex: demoman was limited to 1 per team) and the map pool more refined, . All this process culminated in the refined, fast-paced and interesting metagame we see today.